1. Field of the Invention
The present invention relates to a method, system, and program for maintaining a database of data objects.
2. Description of the Related Art
An object oriented data base system (OODBMS) provides a persistent and sharable repository and manager of objects defined according to an object-oriented data model. Every object encapsulates a state and behavior. The state of an object comprises the values of the attributes (also referred to as properties) defined for the object, and the behavior of the object comprises the methods provided with the objects. Objects that share the same attributes and methods comprise a class. All the objects maintained in an OODBMS are members of the same class or have the same parent class. This means that the same set of methods defined for the class are used to manipulate the objects in the OODBMS, such as create, delete, add, read, modify, update, etc. Further, the objects in a class have the same attributes defined for the class, even though particular attributes within any of the objects in the class may have different values. Objects persistently stored within an OODBMS defined for a class are viewed and distinguished according to the values provided for their attributes. Each object is further provided a unique identifier for use in accessing the object within the OODBMS using the interfaces provided for the class. Benefits and further explanations of object oriented databases are described in “Research Directions in Objected-Oriented Database Systems”, by Won Kim (Copyright Association of Computing Machinery, 1990); “Intermedia: A Case Study of the Differences Between Relational and Object-Oriented Database Systems”, by Karen E. Smith, Stanley B. Zdonik, OOPSLA '87 Proceedings (Copyright Association of Computing Machinery, 1987); and U.S. Pat. No. 6,128,771, all of which publications and patents are incorporated herein by reference in their entirety.
Currently, many object oriented database systems are implemented using a Java application programming interface (API).** The application programmer may write APIs in Java to use to access the object oriented database management system (OODBMS). The interfaces to the objects in the OODBMS are also written in Java, and the objects in the OODBMS are implemented as Java classes. In such Java implemented OODBMS, Java applications can generate Java objects to add to the Java OODBMS and utilize Java APIs to manipulate the Java objects in the Java OODBMS.
One challenge with prior art object oriented database systems is that applications written in different programming languages cannot share objects in the same OODBMS. For instance, a C or C++ application program creating a C or C++ data object cannot add objects to a Java OODBMs because of differences in the naming conventions and structures in the different programming languages. Thus, although two applications written in different languages may utilize the same class of objects having the same attributes and attribute values, and desire to share the same data objects, the applications in the different programming languages cannot store and access objects in the same OODBMS. Due to such limitations, duplicate object oriented databases must be provided for the application programs in the different programming languages even though such application programs intend to use the same data objects instantiated from the same class. Further, one application will not be able to access or manipulate the objects created by the other application and maintained in that applications OODBMS.
For these reasons, there is a need in the art to provide mechanisms to allow application programs in different programming languages to utilize the same OODBMS.